The effect of liquid nitrogen quick-freezer on fish products

2021-05-12 10:00:08

The effect of liquid nitrogen quick-freezer on fish products

Fish and aquatic products mainly contain water, protein, fat, minerals, enzymes and vitamins. Among them, the protein content is relatively high, and there are eight kinds of amino acids necessary for the human body. Compared with livestock and poultry meat, fish and aquatic products have softer muscle tissue, high levels of unsaturated lipase, and high enzyme content.

After the death of fish and aquatic products, there are not only four stages of stiffness, maturation, autolysis and rancidity, but also a process of secretion of surface mucus before stiffness, which is a good culture medium for spoilage bacteria. The above-mentioned four stages have a short duration, especially the softening and maturation stage, which is because a variety of enzymes and microorganisms still have strong activity at lower temperatures. In the autolysis stage, protein and amino acids are decomposed, and spoilage microorganisms multiply, which makes the quality worse.

The storage time of fish and aquatic products is closely related to temperature. Under normal circumstances, the frozen storage period will increase by 3 times for every 10°C decrease in temperature. Fatty fish have a shorter frozen storage period for lower-fat fish, and red muscle fish have a shorter frozen storage period. The general freezing temperature is: the low-fat fish and aquatic products are between -18℃~-23℃; the fatty fish is below -29℃, and some red muscle fish may require a low temperature of -60℃. The lowest possible temperature should be used during freezing and transportation, and any temperature fluctuations should be avoided.

Packaging and operation methods also have an impact on the frozen storage period. The cargo should be prevented from being exposed to the air to cause fat oxidation and dehydration. The loading and unpacking operations should be carried out quickly to avoid temperature fluctuations that affect the quality.

"Ice-coated" fish and aquatic products means covering the surface of the fish and aquatic products with a thin layer of ice to prevent water loss and ensure quality

Nuoruida (Tianjin) science and Technology Co., Ltd. is committed to research, development, and sales of liquid nitrogen freezer. Using European technology, we provide a variety of equipment. The main equipment is liquid nitrogen cryogenic freezer, liquid nitrogen cabinet freezer, liquid nitrogen tunnel freezer,sub-zero processing equipment, cryogenic freezing equipment, and so on.